The palearctic oystercatcher Haematopus ostralegus, a natural definitive host for Gymnophalloides seoi

In order to verify the role of migrating birds as natural definitive hosts for Gymnophalloides seoi (Gymnophallidae), Palearctic oystercatchers, Haematopus ostralegus, were caught from several western coastal areas in the Republic of Korea and examined for intestinal flukes. Five (71.4%) of 7 oystercatchers were infected with 302-1,660 (mean 892) adult G. seoi. In intestinal sections of the host, worms were found in the intervillous space of the mucosal layer. We conclude that the oystercatcher is a natural definitive host for G. seoi.

Reduction of electrically evoked neural activity by ginseng saponin in rat hippocampal slices

It is well established that ginseng saponin has positive influences on various neural diseases, but little is known about its electrophysiological effects in the central nervous system. In this study, we examined the electrophysiological effects of ginseng saponin in rat hippocampal slices. Total saponin from ginseng root reduced the slope of fEPSPs (field excitatory postsynaptic potentials) in the CA1 area in a dose-dependent manner (9.1 +/-5.4%, 48.4+/-12.1%, and 60.5+/-15.3% at 10, 50, and 100 microg/ml, respectively), which was reversed within 10 min of washout. Seven different ginsenosides resulted in varied degrees of fEPSPs reduction. The rank order of reduction was Rb1, Rg1 >Rg2, Rh1, Rc>Rd, Re within a range of 5-64% reduction. No difference in the suppressive action between protopanaxadiol (Rb1, Rc, Rd) and protopanaxatriol (Rg1, Rg2, Re, Rh1) saponins was shown; the slope of fEPSPs was reduced by 38% and 40% on average, respectively. The possible role of gamma-aminobutyric acid (GABA(A)) receptor in the suppressive action of ginseng saponins was tested using whole cell patch recording in acutely isolated hippocampal neurons. Ginsenosides did not induce chloride current nor modified GABA-induced current. Also, the suppressive effect of ginsenosides on fEPSPs was still observed in the presence of the GABA(A) receptor antagonist, bicuculline methiodide 50 microM. These results suggest that the suppressive effect is not attributable to regulation of GABA(A) receptor activation.

The human bone marrow response to acute air pollution caused by forest fires

Atmospheric pollution increases cardiopulmonary morbidity and mortality by unexplained mechanisms. Phagocytosis of fine particles (PM(10)) by rabbit alveolar macrophages elevates white blood cells (WBC) by releasing precursors from the bone marrow and this could contribute to the pathogenesis of cardiopulmonary disease. The present study examined the association between acute air pollution caused by biomass burning and peripheral WBC counts in humans. Serial measurements of the WBC count made during the 1997 Southeast Asian Smoke-haze (Sep 29, Oct 27) were compared with a period after the haze cleared (Nov 21, Dec 5) using peripheral blood PMN band cells to monitor marrow release. The results showed that indices of atmospheric pollution were significantly associated with elevated band neutrophil counts expressed as a percentage of total polymorphonuclear leukocytes (PMN), with maximal association on zero and 1 lag day for PM(10) and 3, and 4 lag days for SO(2) (p value < 0.000). We conclude that atmospheric pollution caused by biomass burning is associated with elevated circulating band cell counts in humans because of the increased release of PMN precursors from the marrow. We speculate that this response contributes to the pathogenesis of the cardiorespiratory morbidity associated with acute air pollution.

Larynx preservation surgery in pyriform sinus cancer

As a general rule, surgery, whenever possible followed by irradiation, is considered to be a standard treatment for pyriform sinus cancer. In early primary lesions, many different approaches have been tried for larynx preservation. From 1990-1997, 7 patients with pyriform sinus carcinoma without the involvement of pyriform sinus apex were treated with partial laryngopharyngectomy at the Asan Medical Center. Three patients were T1 stage and four were T2. All patients had nodal metastases and were treated with neck dissection and postoperative radiotherapy. Follow-up period was 1-8 years. One regional recurrence and one distant metastasis occurred; however, there was no recurrence at the primary site. The voices of all the patients were saved. The most uncomfortable postoperative symptom was mild aspiration. From these results, we can conclude that partial laryngopharyngectomy with neck dissection might be the favorable treatment modality for selected cases of pyriform sinus cancer.

Identification of rice blast fungal elicitor-responsive genes by differential display analysis

In order to study molecular interactions that occur between rice and rice blast fungus upon infection, we isolated fungal elicitor-responsive genes from rice (Oryza sativa cv. Milyang 117) suspension-cultured cells treated with fungal elicitor prepared from the rice blast fungus (Magnaporthe grisea) employing a method that combined mRNA differential display and cDNA library screening. Data base searches with the isolated cDNA clones revealed that the OsERG1 and OsERG2 cDNAs share significant similarities with the mammalian Ca2+-dependent lipid binding (C2) domains. The OsCPX1 cDNA is highly homologous to peroxidases. The OsHin1 cDNA exhibits homology to the tobacco hin1 gene, whose expression is induced by avirulent pathogens. The OsLPL1 and OsMEK1 cDNAs share homologies with lysophospholipases and serine/threonine mitogen-activated protein (MAP) kinase kinases, respectively. The OsWRKY1 and OsEREBP1 cDNAs are homologous to transcription factors, such as the WRKY protein family and the AP2/EREBP family, respectively. Transcripts of the OsERG1, OsHin1, and OsMEK1 genes were specifically elevated only in response to the avirulent race KJ301 of the rice blast fungus. Our study yielded a number of elicitor-responsive genes that will not only provide molecular probes, but also contribute to our understanding of host defense mechanisms against the rice blast fungus.

Selenite negatively regulates caspase-3 through a redox mechanism

Selenium, an essential biological trace element, exerts its modulatory effects in a variety of cellular events including cell survival and death. In our study we observed that selenite protects HEK293 cells from cell death induced by ultraviolet B radiation (UVB). Exposure of HEK293 cells to UVB radiation resulted in the activation of caspase-3-like protease activity, and pretreatment of the cells with z-DEVD-fmk (N-benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethylketone), a caspase-3 inhibitor, prevented UVB-induced cell death. Interestingly, enzymatic activity of caspase-3-like protease in cell lysates of UVB-exposed cells was repressed in vitro by the presence of selenite. Selenite also inhibited the in vitro activity of purified recombinant caspase-3 in cleaving Ac-DEVD-pNA (N-acetyl-Asp-Glu-Asp-p-nitroanilide) or ICAD(L) (inhibitor of a caspase-activated deoxyribonuclease) and in the induction of DNA fragmentation. The inhibitory action of selenite on a recombinant active caspase-3 could be reversed by sulfhydryl reducing agents, such as dithiothreitol and beta-mercaptoethanol. Furthermore, pretreatment of cells with selenite suppressed the stimulation of the caspase-3-like protease activity in UVB-exposed cells, whereas dithiothreitol and beta-mercaptoethanol reversed this suppression of the enzymatic activity. Taken together, our data suggest that selenite inhibits caspase-3-like protease activity through a redox mechanism and that inhibition of caspase-3-like protease activity may be the mechanism by which selenite exerts its protective effect against UVB-induced cell death.

An animal model of neuropathic pain employing injury to the sciatic nerve branches

The present study was conducted to develop a new animal model of neuropathic pain employing injury to the distal sciatic nerve branches. Under halothane anesthesia, the tibial, sural, and/or common peroneal nerves were injured and neuropathic pain behaviors were compared among different groups of rats. Different types of injury produced different levels of neuropathic pain. Rats with injury to the tibial and sural nerves showed the most vigorous mechanical allodynia, cold allodynia, and spontaneous pain. These neuropathic pain behaviors were not relieved by functional sympathectomy using guanethidine. The results suggested that injury to the tibial and sural nerves, while leaving the common peroneal nerve intact, can be used as a new animal model of neuropathic pain and that this model represents sympathetically independent pain (SIP). The present animal model is very simple to produce injury and can produce profound and reliable pain behaviors. These features enable the new animal model to be a useful tool in elucidating the mechanisms of neuropathic pain, especially SIP.

Stretch-activated and background non-selective cation channels in rat atrial myocytes

1. Stretch-activated channels (SACs) were studied in isolated rat atrial myocytes using the whole-cell and single-channel patch clamp techniques. Longitudinal stretch was applied by using two patch electrodes. 2. In current clamp configuration, mechanical stretch of 20 % of resting cell length depolarised the resting membrane potential (RMP) from -63.6 +/- 0.58 mV (n = 19) to -54.6 +/- 2.4 mV (n = 13) and prolonged the action potential duration (APD) by 32.2 +/- 8.8 ms (n = 7). Depolarisation, if strong enough, triggered spontaneous APs. In the voltage clamp configuration, stretch increased membrane conductance in a progressive manner. The current-voltage (I-V ) relationship of the stretch-activated current (ISAC) was linear and reversed at -6.1 +/- 3.7 mV (n = 7). 3. The inward component of ISAC was abolished by the replacement of Na+ with NMDG+, but ISAC was hardly altered by the Cl- channel blocker DIDS or removal of external Cl-. The permeability ratio for various cations (PCs:PNa:PLi = 1.05:1:0.98) indicated that the SAC current was a non-selective cation current (ISAC,NC). The background current was also found to be non-selective to cations (INSC,b); the permeability ratio (PCs:PNa:PLi = 1.49:1:0.70) was different from that of ISAC,NC. 4. Gadolinium (Gd3+) acted on INSC,b and ISAC,NC differently. Gd3+ inhibited INSC,b in a concentration-dependent manner with an IC50 value of 46.2 +/- 0.8 microM (n = 5). Consistent with this effect, Gd3+ hyperpolarised the resting membrane potential (-71.1 +/- 0.26 mV, n = 9). In the presence of Gd3+ (0.1 mM), stretch still induced ISAC,NC and diastolic depolarisation. 5. Single-channel activities were recorded in isotonic Na+ and Cs+ solutions using the inside-out configuration. In NMDG+ solution, outward currents were abolished. Gd3+ (100 microM) strongly inhibited channel opening both from the inside and outside. In the presence of Gd3+ (100 microM) in the pipette solution, an increase in pipette pressure induced an increase in channel opening (21.27 +/- 0.24 pS; n = 7), which was distinct from background activity. 6. We concluded from the above results that longitudinal stret in rat atrial myocytes induces the activation of non-selective cation channels that can be distinguished from background channels by their different electrophysiology and pharmacology.

Cloning and characterization of cDNA encoding zebrafish Danio rerio NM23-B gene

A full-length zebrafish NM23-B cDNA was cloned and sequenced. The zebrafish NM23-B cDNA consists of 624bp with an open reading frame of 153 amino acids. NM23-B mRNA of approximately 0.7kb is present in adult zebrafish tissues. Zebrafish NM23-B his-tagged protein (17kDa) was produced in E. coli and characterized by binding and UV-cross-linking to a single-stranded telomeric repeat (TTAGGG)(6). This is the first report to show that fish have a NM23-H2 homologue that is similar to that in humans.

Early expression of angiogenesis factors in acute myocardial ischemia and infarction

BACKGROUND

When the myocardium is deprived of blood, a process of ischemia, infarction, and myocardial remodeling is initiated. Hypoxia-inducible factor 1 (HIF-1) is a transcriptional activator of vascular endothelial growth factor (VEGF) and is critical for initiating early cellular responses to hypoxia. We investigated the temporal and spatial patterns of expression of the alpha subunit of HIF-1 (HIF-1alpha) and VEGF in specimens of human heart tissue to elucidate the early molecular responses to myocardial hypoxia.

METHODS

Ventricular-biopsy specimens from 37 patients undergoing coronary bypass surgery were collected. The specimens were examined by microscopy for evidence of ischemia, evolving infarction, or a normal histologic appearance. The specimens were also analyzed with the reverse-transcriptase polymerase chain reaction for HIF-1alpha and VEGF messenger RNA (mRNA) expression and by immunohistochemical analysis for the location of the HIF-1alpha and VEGF proteins.

RESULTS

HIF-1alpha mRNA was detected in myocardial specimens with pathological evidence of acute ischemia (onset, <48 hours before surgery) or early infarction (onset, <24 hours before surgery). In contrast, VEGF transcripts were seen in specimens with evidence of acute ischemia or evolving infarction (onset, 24 to 120 hours before surgery). Patients with normal ventricles or evidence of infarction in the distant past had no detectable levels of either VEGF mRNA or HIF-1alpha mRNA. HIF-1alpha immunoreactivity was detected in the nuclei of myocytes and endothelial cells, whereas VEGF immunoreactivity was found in the cytoplasm of endothelial cells lining capillaries and arterioles.

CONCLUSIONS

An increase in the level of HIF-1alpha is an early response to myocardial ischemia or infarction. This response defines, at a molecular level, one of the first adaptations of human myocardium to a deprivation of blood. HIF-1alpha is a useful temporal marker of acutely jeopardized myocardium.

High endemicity of Metagonimus yokogawai infection among residents of Samchok-shi, Kangwon-do

A small-scale epidemiological survey was undertaken during 1997-1998 on the residents along the Osib-chon (Stream), Samchok-shi (City), Kangwon-do (Province), to evaluate the status of Metagonimus yokogawai infection. A total of 165 fecal samples was collected and examined by cellophane thick smear and formalin-ether sedimentation techniques. The egg positive rate of M. yokogawai was 29.7%, showing a remarkable difference between males (46.6%) and females (16.3%). To obtain the adult flukes of M. yokogawai, 11 egg positive persons were treated with praziquantel and purged with magnesium sulfate. A total of 242,119 adult flukes (average 22,010 per person, 367-119,650 in range) was collected from diarrheic stools, all of which were identified as M. yokogawai. The results show that M. yokogawai is still highly endemic in this area.

Insulin sensitivity in normotensive offspring of hypertensive parents

OBJECTIVES

To investigate the insulin sensitivity in normotensive offspring of hypertensive parents.

SUBJECTS

Fifteen young normotensive offspring of hypertensive parents were paired with 15 controls matched for age, sex and body mass index.

METHODS

The insulin sensitivity was investigated by 75 g oral glucose tolerance test (OGTT) and modified insulin suppression test. A high-fat mixed meal was administered to observe the changes of TG levels.

RESULTS

The plasma glucose and serum insulin responses to oral glucose challenge were comparable between both groups. High-fat mixed meal made no difference in the plasma glucose, serum triglyceride or insulin between the 2 groups. With the modified insulin suppression test, the steady-state plasma glucose levels (SSPG) were higher in the offspring of parents with essential hypertension (138+/-43 mg/dl) than in the control group (95+/-26 mg/dl). The diastolic blood pressure and heart rate of the offspring of hypertensive parents are also higher than the control group.

CONCLUSIONS

Insulin resistance exists in young normotensive offspring of hypertensive parents, and the impairment of insulin-mediated glucose uptake in these subjects develop before any alteration of fasting and postprandial triglyceride.

Absence of mutations in the kinase domain of the Met gene and frequent expression of Met and HGF/SF protein in primary gastric carcinomas

Hepatocyte growth factor/scatter factor (HGF/SF) and its receptor, Met, are known to play important roles in tumor cell migration, invasion, and metastasis. We analyzed the expression of these genes and the mutations in the kinase domain of the Met gene in 43 gastric carcinomas. Of the 43 cases, the Met and HGF/SF protein were expressed in 29 (67%) and 22 (51%), respectively. All of the cases with HGF/SF immunopositivity also expressed Met. Of 22 cases with HGF/SF immunopositivity, 13 (59%) expressed HGF/SF in tumor cells as well as fibroblasts. We detected no aberrant single-strand conformational polymorphism patterns, suggesting that there are no genetic alterations in the kinase domain of the Met gene. These results indicate that HGF/SF-mediated autocrine and/or paracrine stimulation and overexpression rather than structural alteration of its receptor may contribute to the development and progression of gastric carcinoma, and that expression of Met and HGF/SF may confer a growth advantage to neoplastic cells.

Surface ultrastructure of Metagonimus takahashii metacercariae and adults

A scanning electron microscopic study was performed on the surface ultrastructure of metacercariae and adults of Metagonimus takahashii. Metacercariae were collected from the scale of crucian carp (Carassius auratus), and adult flukes were harvested 1-4 weeks after infection to rats. In excysted metacercariae, the oral sucker had type I (numerous) and type II (seven in total) sensory papillae. Tegumental spines were dense and digitated into 5-7 points on the surface anterior to the ventral sucker, but became sparse and less digitated posteriorly toward the end of the body. In adults, seven type II sensory papillae were characteristically arranged around the lip of the oral sucker, and on the inner side of the lip four small and two large type I sensory papillae were symmetrically seen on each side (12 in total). Tegumental spines on anterior two-thirds of the body, were digitated with 9-12 tips ventrally and 8-13 tips dorsally. Sperms entering into the Laurer's canal were observed. The results show that the surface ultrastructure of M. takahashii is generally similar to those of M. yokogawai and M. miyatai except for the digitation of tegumental spines.

In vitro blastocyst formation of human oocytes obtained from unstimulated and stimulated cycles after vitrification at various maturational stages

OBJECTIVE

To evaluate the developmental competence and chromosomal normality of oocytes vitrified at various times after maturation culture.

DESIGN

In vitro model study.

SETTING

A university-affiliated hospital.

PATIENT(S)

Unstimulated women who underwent cesarean section or oophorectomy and infertile women who underwent a long protocol of GnRH stimulation.

INTERVENTION(S)

Retrieved oocytes were vitrified at 0 or 48 hours after culture in unstimulated cycles and at 0, 8-15, or 24-28 hours after culture in stimulated cycles.

MAIN OUTCOME MEASURE(S)

Postthaw morphologic normality, maturation, fertilization, cleavage, blastocyst formation, and chromosome number.

RESULT(S)

In the 53 oocytes that were obtained from unstimulated cycles, no statistically significant differences were found in rates of morphologic normality (range, 56%-63%) or fertilization (range, 31%-37%) according to the time of vitrification. In the 50 oocytes that were obtained from stimulated cycles, more of those that were vitrified at 24-28 hours were morphologically normal than those that were vitrified at 0 or 8-15 hours. Regardless of these differences, high cleavage rates (83%-100%) were obtained that did not differ significantly among the treatment groups. In both cycles, 20%-43% of cleaved oocytes developed to the blastocyst stage by 6 days after IVF. All the karyotyped blastocysts, three from unstimulated cycles and four from stimulated cycles, had a normal number of chromosomes.

CONCLUSION(S)

Vitrified and thawed oocytes from unstimulated or stimulated cycles developed to the blastocyst stage, regardless of when vitrification occurred; the number of chromosomes in the blastocysts was normal.

Establishment of a phagocytic cell line from Bombina orientalis

Continuous serum-free culture of Bok-2 cells was generated from primary culture of the tail bud stage embryos of the toad, Bombina orientalis. Bok-2 cells can be maintained in modified L-15 serum-free medium prepared by mixing L-15 medium, lactalbumin enzymatic hydrolysate, sucrose and sodium bicarbonate. Bok-2 cells have an ameboid behavior and morphology. When Bok-2 and viable Candida albicans were co-cultured, Bok-2 cells showed an immune response characterized by chemotaxis, phagocytosis and partial clearing activity of Candida cells and colonies. And Bok-2 cells also showed phagocytosis of latex beads without serum treatment and displayed numerous pseudopodia, membrane evagination for phagocytosis and phagosome activity. On the basis of these results, Bok-2 cells were identified as professional phagocytes.

IgG antibodies to type II collagen reflect inflammatory activity in patients with rheumatoid arthritis

OBJECTIVE

To determine the clinical significance of IgG antibodies to type II collagen (CII) and to define any correlation of antibodies to CII with the inflammatory response in patients with rheumatoid arthritis (RA).

METHODS

IgG antibodies to native human type II collagen (IgG anti-CII) were measured in sera and synovial fluid (SF) from patients with RA, patients with osteoarthritis (OA), and healthy controls by an improved ELISA. Demographic, clinical, and laboratory data including tumor necrosis factor-alpha (TNF-alpha) and interleukin 6 (IL-6) levels were also obtained at the time of sampling in patients with RA.

RESULTS

The median level and positivity for circulating IgG anti-CII were higher in patients with RA (n = 297) than patients with OA (n = 34) and healthy controls (n = 50) (p < 0.001). The titers of IgG anti-CII in SF were also higher in RA (n = 45) than in OA (n = 16) (p < 0.001). In paired samples, the levels of IgG anti-CII were significantly higher in SF compared to the sera in patients with RA (n = 45) (p < 0.001), but levels were not different in patients with OA (n = 16). Circulating IgG anti-CII converted from positive to negative in 13 patients (10.7%) and from negative to positive in 18 patients (14.8%) among 122 patients with RA in whom IgG anti-CII were monitored sequentially at a mean interval of 12.2 months. IgG anti-CII positive patients (n = 98) had shorter disease duration (p = 0.04) and less frequent deformity (p = 0.013), and higher median erythrocyte sedimentation rate (ESR) (p = 0.001) and C-reactive protein (CRP) (p < 0.001) than IgG anti-CII negative patients (n = 120). The levels of IgG anti-CII correlated with CRP (r = 0.270) and ESR (r = 0.253). CRP decreased significantly in patients (n = 13) who converted from IgG anti-CII positive to negative (p = 0.013). IgG anti-CII positive patients (n = 40) had higher levels of TNF-alpha and IL-6 than negative patients (n = 40) (p < 0.001). Levels of IgG anti-CII correlated well with TNF-alpha (r = 0.617) and IL-6 (r = 0.347).

CONCLUSION

Increased IgG anti-CII in sera and SF in RA correlated directly with acute phase reactants and the proinflammatory cytokines TNF-alpha and IL-6. Our data suggest that IgG anti-CII could reflect inflammatory activity with a potential to destroy cartilage in the early stages of RA.

Significance of acute multiple brain infarction on diffusion-weighted imaging

BACKGROUND AND PURPOSE

Diffusion-weighted imaging (DWI) is superior to conventional MRI in identification of small new ischemic lesions and discrimination of recent infarcts from old ones. Thus, this technique is useful in the detection of acute multiple brain infarcts (AMBI). We sought to determine the frequency and the topographical and etiologic patterns of AMBI detected on DWI.

METHODS

We studied 329 consecutive ischemic stroke patients who underwent DWI and MRI/MR angiography within 4 days of stroke onset. AMBI was defined as noncontiguous high signal intensities on DWI in >1 vascular territory. Stroke mechanism was determined according to the criteria of the Trial of Org 10172 in Acute Stroke Treatment (TOAST).

RESULTS

We detected AMBI in 95 patients (28.9%). AMBI in anterior circulation was found in 62 cases: in 1 hemisphere in 42 (group A) and in bilateral hemispheres in 20 (group B). Twenty-two patients had AMBI in the posterior circulation (group C) and 11 in both anterior and posterior circulations (group D). The most frequent cause of stroke was large-artery atherosclerosis in groups A (33/42), B (9/20), and C (15/22) (P=0.02) and cardioembolism in group D (6/11) (P=0.02). Elevated fibrinogen or hematocrit was significantly associated with group B (P=0.01). In 9 patients in groups B and D, anatomic variations of anterior or posterior cerebral arteries or patent posterior communicating artery contributed to AMBI.

CONCLUSIONS

Different topographical patterns of AMBI are associated with different vascular pathologies and stroke mechanisms. Hemorheologic abnormality or vascular anatomic variations may be contributing factors in the pathogenesis of AMBI in bilateral cerebral hemispheres or in both anterior and posterior circulations.

Characterization of Borrelia burgdorferi strains isolated from Korea by 16S rDNA sequence analysis and PCR-RFLP analysis of rrf (5S)-rrl (23S) intergenic spacer amplicons

Haenam strains of Borrelia burgdorferi, which had been isolated from Ixodes granulatus and Apodemus agrarius in Haenam, Korea, were characterized by PCR-RFLP analysis of rrf (5S)-rrl (23S) intergenic spacer amplicons and by sequence analysis of the 16S rRNA gene (rDNA). The Msel and Dral restriction patterns of the 5S-23S intergenic spacer amplicons of Haenam strains differed from those of other B. burgdorferi sensu lato strains. Furthermore, in the phylogenetic tree based on the 16S rDNA sequences, Haenam strains formed a distinctive cluster, clearly separated from the other members of B. burgdorferi sensu lato. These results suggest that, apart from Borrelia garinii and Borrelia afzelii, other genotypes of B. burgdorferi sensu lato exist in Korea and the Haenam strain is a newly identified one.

Effect of arachidonic acid metabolic inhibitors on hypoxia/reoxygenation-induced renal cell injury

The present study was undertaken to examine the role of arachidonic acid (AA) metabolites in hypoxia/reoxygenation (H/R)-induced renal cell injury in rabbit renal cortical slices using AA metabolic inhibitors. Inhibitors of cyclooxygenase (indomethacin and diclofenac sodium) and lipoxygenase pathways (nordihydroguaiaretic acid, caffeic acid, and eicosapentaenoic acid) reduced H/R-induced LDH release in a dose-dependent manner, whereas an inhibitor of cytochrome P-450 monooxygenase pathway ethoxyresorufin was not effective. AA increased LDH release in control slices, and the effect was not altered by indomethacin and nordihydroguaiaretic acid. The protective effect of indomethacin was not affected by addition of PGE2, a main product of cyclooxygenase pathway in the kidney. H2O2-induced LDH release was prevented by inhibitors of lipoxygenase but not by inhibitors of cyclooxygenase and cytochrome P-450 monooxygenase H/R-induced LDH release was not altered by iron chelators, phenanthroline and deferoxamine, and a potent antioxidant, N,N'-diphenyl-p-phenylenediamine, suggesting that the H/R-induced cell injury is not attributed to a generation of reactive oxygen species. Morphological studies showed that H/R-induced structural changes including cell necrosis were significantly prevented by indomethacin. These results suggest that inhibitors of cyclooxygenase and lipoxygenase pathways exert a direct protective effect against the H/R-induced cell injury in renal tubules. Whether these effects are mediated by alterations of AA metabolic pathways is not certain.

Epstein-Barr virus early ribonucleic acids as a diagnostic adjunct for relapsed metastatic tumors in patients with cured primary undifferentiated nasopharyngeal carcinoma

PURPOSE

Epstein-Barr virus (EBV) has been consistently shown to be associated with undifferentiated nasopharyngeal carcinoma (NPC). In this article, the authors attempt to detect Epstein-Barr virus in distant relapsed metastatic sites in undifferentiated NPC patients with cured primary cancer.

MATERIALS AND METHODS

In situ hybridization (ISH) technique is a reliable method to detect EBV early RNAs (EBERs) within NPC cells. We used a nonisotopical ISH technique to examine the presence of EBERs in paraffin-embedded tissues obtained from 1 paired specimen of primary NPC and its metastatic counterpart at liver and 2 metastatic specimens of retroperitoneal lymph nodes and bone.

RESULTS

All the primary lesions and the metastatic tumors of NPC with undifferentiated histology contained EBERs that could be clearly detected in the nuclei of cancer cells.

CONCLUSIONS

This article shows that EBERs can be successfully detected in cells of the distant relapsed metastatic sites. These results suggest that this nonisotopical ISH method of EBERs can be potentially used to diagnose NPC patients developing distant relapsed metastatic lesions with cured primary cancer early. It can offer quick information as to institute suitable salvage chemotherapy for these patients.